This was my first time hatching eggs of any sort, so I wanted to see how it would go by doing NOTHING....I pretty much ignored her and let her do whatever she wanted. I watched to make sure she didnt get sickly or weak from not eating, but some days she didnt get up at all, some days she was out for a couple hours at a time! The eggs were not expensive, so all I really had to lose was ten bucks. I thought, "I dont want to do this if it is going to be a lot of work!" In the end I moved her to a new coop on day 18 or so, to keep the babies safe. Now that I have the second coop, I will likely separate the broody, but otherwise I will just leave them alone. 4/6 hatched, and the two that didnt might not have been fertile to start with- I dont know. One died within hours, but the other 3 are growing like weeds! Ill give her more eggs next time- probably a dozen.
Also, someone asked about breeds, mine is a Black Copper Marans. I also have a Blue Copper Marans who was broody about a week later, but I just ignored her and she snapped out of it after a few weeks. (I didnt have more eggs, but hopefully when they do this again in the spring and hatching eggs are everywhere, I will let everyone have eggs!)